Floods in glacial lakes threaten about 15 million – 07/02/2023 – Environment

Melting mountain glaciers pose a growing risk of flooding for some 15 million people worldwide, researchers said in a report published on Tuesday, with communities in Asia facing the greatest danger.

Runoff from melting glaciers often collects in shallow lakes, held back by rocks and debris. The risk arises when a lake bursts its banks, breaching its natural barrier and sending a torrent of water down mountain valleys.

Scientists have assessed for the first time how many people around the world are at risk from these floods, finding that more than half of vulnerable populations live in India, Pakistan, China and Peru.

The danger is greatest, they report in a study published in the journal Nature Communications, when large numbers of people live near a lake.

“Our work doesn’t just focus on the size or number of glacial lakes — no disaster is natural — it’s the presence of people, especially vulnerable people, in the landscape that causes a disaster,” said Stuart Dunning, a physical geographer at Newcastle University and co-author of the study.

Glacial lake burst flooding is predicted to get worse in warmer weather.

Collectively, the world’s glaciers lost about 332 gigatons of ice per year between 2006 and 2016. Since 1990, the number and volume of glacial lakes worldwide has increased by about 50%.

In the high mountains of Asia, around 9 million people live near more than 2,000 glacial lakes. In 2021, more than a hundred people died in India in a flood in the northern mountains.